Science: Weight loss revealed! Time-restricted eating during the active phase of the day increases adipocyte thermogenesis and weight loss

The eating rhythm is inconsistent with the light-dark cycle, leading to peripheral circadian clock disturbances and obesity
.
Conversely, restricting eating to the active phase of the light-dark cycle can alleviate metabolic syndrome
through an unknown mechanism.

In a new study, researchers from Northwestern University and the University of Texas Southwestern Medical Center found that increased thermogenesis of fat cells during the active phase of the daily circadian rhythm could limit weight gain
in mice.
The results of the study were published in the October 21, 2022 issue of the journal Science in the paper "Time-restricted feeding mitigates obesity through adipocyte thermogenesis"
。 Damien Lagarde and Lawrence Kazak of McGill University in Canada published an opinion-type article titled "The timing of eating controls energy use" in the journal Science at the same time, outlining their work
in the new study.

Previous studies have shown that overeating during the inactive phase of circadian rhythms in mice and humans leads to higher levels of weight gain
.
Similarly, adherence to time-restricted feeding (TRF) can lead to less weight gain
.
But until then, why this happened has not been fully understood
.

To further understand the effects of a high-fat diet on mice at various stages of circadian rhythms, the authors fed two groups of mice a high-fat diet
.
One group ate during their active phase (when it was dark) and the other ate during their inactive phase (when it was dawn).

They then took a closer look at what
was happening in the fat cells of both groups of mice.

The authors found that, as expected, mice that ate in the inactive phase gained more
weight.
But they also learned more about the factors
behind this weight gain.
One of the biggest factors is thermogenesis, the process of
generating heat in the body.
They found that during the active phase of the circadian rhythm, an increase in thermogenesis in fat cells (due to an increase in creatine in fat cells) was at least part of the reason for
limiting weight gain.

In vivo and in vitro, the loss of BMAL1 in adipocytes impairs creatine biosynthesis and circulation
.
Image from Science, 2022, doi:10.
1126/science.
abl8007
.

They also found that a zinc finger protein called ZFP423 can block genes
responsible for producing chemicals that regulate thermogenesis by controlling the production of adenosine triphosphate (ATP).
Enhancing the thermogenic effect of adipocytes by eliminating ZFP423 attenuates obesity
caused by high-fat diet intake in the inactive phase.
Circadian control of creatine metabolism in adipocytes is the temporal basis for diet-induced thermogenesis, and enhancing adipocyte circadian rhythms through overexpression of the clock-activating protein BMAL1 (brain and muscle Arnt-like protein-1) can improve metabolic complications
during diet-induced obesity.
Based on this, they revealed that rhythmic creatine-mediated thermogenesis is the fundamental mechanism
that drives metabolic benefits during time-restricted eating.

Taken together, the new study helps explain why time-restricted eating can play such an important role
in weight management.

Resources:

Chelsea Hepler et al.
 Time-restricted feeding mitigates obesity through adipocyte thermogenesis.
Science, 2022, doi:10.
1126/science.
abl8007.

Damien Lagarde et al.
 The timing of eating controls energy use.
Science, 2022, doi:10.
1126/science.
ade6720.